This invention relates to an ultrasonic flow meter device for measuring the flow rate of a high temperature fluid flowing through a pipe.
Conventional ultrasonic flow meters have generally included one connector connecting each of several ultrasonic transmitters and receivers to the particular pipe through which a fluid to be measured flows, and oil or grease fills gaps formed on the interfaces between the connector and the mating transmitter or receiver and between the connector and the outer wall surface of the pipe. The purpose of the oil or grease is to increase the transmissibility of the ultrasonic waves on these interfaces. With the measured fluid maintained at a temperature as high as about 500.degree. C, such as molten alkali metals, the oil or grease filling the gaps as above described can not remain intact. Thus such ultrasonic flow meters have not been capable to measuring the flow rate of high temperature fluid.